Enhancing the flash-sinterability of BaZr0.1Ce0.7Y0.2O3-δ proton-conducting electrolyte by nickel oxide doping for possible application in SOFCs

In the present work, effects of nickel oxide doping on flash-sinterability of BaZr_0.1Ce_0.7Y_0.2O_3-δ compound were investigated. A single-phase BZCY7 powder was synthesized by the solid-state reaction route. The effects of using 0.5, 1, 1.5, and 2 wt% of NiO additive on flash sintering of BZCY7 samples were examined. It was revealed that using 0.5 wt% of NiO additive can reduce the onset temperature of flash sintering in all the applied electric fields in the range of 100–500 V/cm and significantly enhances the sinterability of the BZCY7 compound. Microstructural investigations, using field emission scanning electron microscopy and energy-dispersive X-ray mapping, showed that NiO doping can lead to larger grain sizes, while no detectable segregation or second phase was observed. Utilizing electrochemical impedance spectroscopy, the total conductivity of samples at 600 and 700 °C was measured as 4.4 × 10^?3 and 7.0 × 10^?3 S/cm for the undoped BZCY7, and 8.6 × 10^?3 and 1.4 × 10^?2 S/cm for the 0.5 wt% NiO doped BZCY7 sample, respectively. The activation energies of conduction were determined as 0.37 and 0.41 eV for the doped and undoped samples, which represent the presence of predominant and facile protonic conduction.     

Performance Analysis of Contact Baking of Flat Bread in an Indirect-Heating Oven

A significant portion of Iranian flat breads are produced in semi-industrial, indirect-heating ovens. Therefore, an efficient oven design and a proper selection of operating conditions are crucial to improve the product quality and reduce energy consumption. In the present study, a mathematical model is developed to simulate a semi-industrial, indirect-heating, continuous oven performance during contact baking of an Iranian flat bread, referred to as Taftoon. Individual modes of heat transfer are considered among various components of the baking system to estimate the system performance and the bread quality in terms of design and operating conditions. The predictions of this model are in good agreement with the experimental data. Numerical results indicate that conduction is the primary heat transfer mechanism. Furthermore, the effects of dough thickness, conveyer speed, and input air velocity on the quality of the bread are studied and appropriate ranges for the parameters are determined.     

Respiratory burst activity of blood and milk neutrophils in dairy cows during different stages of lactation.

The non-stimulated and phorbol 12-myristate 13-acetate (PMA)-stimulated luminol-augmented cellular chemiluminescence (CL) response and viability of milk and blood polymorphonuclear leukocytes (PMN) were determined in lactating dairy cows during different stages of lactation. In the first study, ten healthy cows each in early, mid and late lactation were compared. In a second study, the same measurements as in the first study were evaluated longitudinally in 12 cows during 1 month following parturition. The CL activity and myeloperoxidase (MPO) content of milk PMN and macrophages (M) were also compared. Milk M did not possess MPO activity and were devoid of any luminol-enhanced CL. The CL activity of milk and blood PMN was significantly lower in early lactation than in mid and late lactation (P < 0.001). Whereas little changes were observed in viability of blood PMN, the viability of milk PMN was lower in early lactation than in mid and late lactation (P < 0.001). The percentage of PMN in isolated milk cells was also lower during early lactation than during mid and late lactation (P < 0.001). The CL activity in response to PMA during early, mid and late lactation increased 13, 59 and 42-fold in blood PMN and 1.7, 2.6 and 2.4-fold in milk PMN, respectively, in comparison with non-stimulated PMN. The CL activity, both in milk and blood PMN. the milk PMN viability and the percentage of milk PMN were lowest between 3 d and 11 d post partum. These observed changes immediately after calving could contribute to a higher susceptibility to mastitis in that period.     

Ovariectomy-induced bone loss and the hematopoietic system

To investigate the relationship of the hematopoietic system to the loss of bone due to ovarian hormone deficiency, we examined the effects of ovariectomy and estrogen administration on the thymus, spleen and the bone marrow, and on the proliferation of marrow progenitors of osteoclasts. We also assessed the effects of daily administration of interleukin-1 receptor antagonist (IL-1ra) on bone loss due to ovarian hormone deficiency. Ovariectomy resulted in decreased cancellous bone volume, increased trabecular osteoblast and osteoclast numbers, and increased serum alkaline phosphatase levels that were prevented by 17 beta-estradiol treatment. Thymus weight, spleen weight, thymus and spleen lymphocytes, and bone marrow monocytes and lymphocytes also increased significantly following ovariectomy, and the increases were suppressed by 17 beta-estradiol. Ovariectomy, in addition, caused a 4-fold increase in the number of tartrate resistant acid phosphatase (TRAP)-positive multinucleated cells formed in cultures of marrow cells and the increase was partially inhibited by 17 beta-estradiol. IL-1ra administration did not prevent the bone loss due to ovariectomy. Our findings indicate that ovariectomy-induced bone loss in the rat is accompanied by marked changes in the hematopoietic system, and that these changes are modulated by estrogen administration. In spite of the negative finding with IL-1ra, the nature of the involvement of the hematopoietic system in the pathogenesis of bone loss due to ovarian hormone deficiency merits continued exploration.     

Soy protein supplementation does not cause lymphocytopenia in postmenopausal women

Background  

The health benefits of soy isoflavones have been widely investigated; however, there are some concerns as to whether soy isoflavones, similar to ipriflavone, a synthetic isoflavone, cause lymphocytopenia in postmenopausal women. Hence, the purpose of this study was to investigate the extent to which 12-month supplementation of 25 g soy protein containing 60 mg isoflavones alters lymphocyte counts or other hematological parameters in postmenopausal women who were not on hormone replacement therapy.     

Characteristics of date pit oil

Date pit oils of three Iranian varieties of dates were examined for their fatty acid composition and some of their characteristics. The properties and compositions of the pit oils did not differ significantly from each other or from previously published literature values.     

Increase in Escherichia coli inoculum dose accelerates CD8+ T-cell trafficking in the primiparous bovine mammary gland

Although migration of leukocytes into the mammary gland is pivotal for a cow's response against intramammary invading pathogens, the contribution of lymphocyte subsets to this response remains unclear. To investigate the dynamics of lymphocyte populations during Escherichia coli mastitis, T-lymphocyte subsets, CD4⁺/CD8⁺ ratio, CD21⁺ cells, and lymphoproliferation were studied in blood and milk of primiparous cows exposed to different quantities of bacteria. The cows were intramammarily inoculated with 10⁴ cfu of E. coli (group A) and 10⁶ cfu (group B). Compared with group A, a much greater number of lymphocytes migrated into the infected quarters at postinfection hour (PIH) 6 to 24 in group B, and the CD8⁺ cells were the first-recruited T cells in the milk. There was a significant decline in the CD4⁺/CD8⁺ ratios at PIH 6 to 24 in group B. The decrease of CD4⁺/CD8⁺ ratios at PIH 6 to 24 resulted mainly from greater CD8⁺ cell concentrations in milk. In contrast, at PIH 72, CD4⁺/CD8⁺ ratios increased about 2-fold in both groups. This increase was mainly due to the increase in CD4⁺ cell concentration. The increased concentration of CD4⁺ cells coincided with an increase in the CD21⁺ cell population in the milk. In blood, the increase of CD8⁺ cells appeared much faster in group B (PIH 6 and 12) than in group A. The results from lymphoproliferation also indicated a greater increase in the proliferative response in both blood and milk lymphocytes of group B. Our study demonstrates for the first time that an increase of E. coli inoculum dose accelerates the trafficking of CD8+ cells during initiation of E. coli mastitis, and these cells are the predominant T cells in milk during the early hours of bovine E. coli mastitis.     

Evaluation of Polycyclic Aromatic Hydrocarbons Contamination in the Sediments of the Johor Strait,Peninsular Malaysia

In May 2013, sediment samples were collected from five stations in the Straits of Johor, near the southern tip of Peninsular Malaysia, in order to evaluate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 United States Environmental Protection Agency PAHs varied from 650.5 to 1441.2 ng g ^?1 dry weight (dw) with a mean value of 985.5 ng g ^?1 dw. PAHs can be classified as moderate level pollution in the collected samples. When comparing PAHs in this study with that of the sediment quality guidelines (SQGs), it was found that the total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs might incur minimal adverse biological effects. The diagnostic ratios of individual PAHs indicated both petrogenic and pyrogenic origins with predominantly pyrogenic sources, the findings of which are further supported by the results from principal component analysis (PCA). The PCA results reveal contributions of 44.44%, 32.3%, and 18.96% for traffic-related, coal combustion, and petroleum-related products, respectively. These findings indicate that the effective monitoring and significant improvement resulting from the implementation of environmental regulations in Malaysia might have caused a shift in the source of petroleum hydrocarbons in the Straits of Johor's aquatic ecosystems from petrogenic to pyrogenic origins.     

Effect of core–shell rubber toughening on mechanical,thermal, and morphological properties of poly(lactic acid)/multiwalled carbon nanotubes nanocomposites

The effect of core–shell rubber (CSR) toughening on mechanical and thermal properties of poly(lactic acid)/multiwalled carbon nanotubes (PLA/CNT) nanocomposites were investigated. The nanocomposites were prepared by direct melt blending method in a counter-rotating twin-screw extruder. The contents of CSR were varied between 5 and 20 wt % while the content of CNT was kept at 5 phr. The extruded samples were injection molded into the desired test specimens for mechanical and thermal properties analysis. The impact strength of PLA/CNT increased with increasing CSR content with concomitant decrease in tensile strength and modulus. Interestingly, the flexural strength increased at low CSR content before decreasing at 15 and 20% content. Differential scanning calorimetry analysis on the second heating cycle shows no crystallinity content for PLA/CNT and all CSR toughened PLA/CNT nanocomposites, while thermogravimetric analysis shows lower thermal degradation of all CSR toughened PLA/CNT as compared to PLA/CNT nanocomposite. This study reveals significant correlation between CSR loading with the mechanical and thermal properties of the nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47756.     

Application of Exponential-Based Methods in Integrating the Constitutive Equations with Multicomponent Nonlinear Kinematic Hardening

The von-Mises plasticity model, in the small strain regime, along with a class of multicomponent nonlinear kinematic hardening rules is considered. The material is assumed to be stabilized after several load cycles and therefore, isotropic hardening will not be accounted for. Application of exponential-based methods in integrating plasticity equations is provided, which is based on defining an augmented stress vector and using exponential maps to solve a system of quasi-linear differential equations. The solutions obtained by this new technique give very accurate updated stress values that are consistent with the yield surface. The classical forward Euler method is reformulated in details and applied to the multicomponent form of the nonlinear kinematic hardening in order to provide a comparison for the suggested technique. Moreover, a consistent tangent operator for the exponential-based integration strategy and also for the classical forward Euler algorithm is presented. In order to show the robustness and performance of the proposed formulation, an extensive numerical investigation is carried out.